WO2015151150A1

WO2015151150A1 - Plasma treatment device and coil used therein

Info

Publication number: WO2015151150A1
Application number: PCT/JP2014/059432
Authority: WO
Inventors: 利泰速水; 俊也宮▲崎▼
Original assignee: Ｓｐｐテクノロジーズ株式会社
Priority date: 2014-03-31
Filing date: 2014-03-31
Publication date: 2015-10-08
Also published as: EP3128819A1; KR101529498B1; JPWO2015151150A1; US20160358748A1; JP5638727B1

Abstract

A plasma etching device is provided with: a chamber that is configured so as to comprise a treatment space and a plasma generation space (4); a coil (20) that is wrapped around a treatment chamber (2); and the like. Six inwardly protruding sections (21) that protrude farther inward in the radial direction than a pitch circle (P) that is set on the outside of a part of the treatment chamber (2) that corresponds to the plasma generation space and five outwardly protruding sections (22) that protrude farther outward in the radial direction than the pitch circle (P) are continuously formed in the coil (20). The six inwardly protruding sections (21), the five outwardly protruding sections (22), and a gap section between power introduction sections (20a) and (20b) are arranged at equal intervals in an alternating manner along the circumferential direction of the pitch circle (P).

Description

Plasma processing apparatus and coil used in the same

The present invention relates to a plasma processing apparatus for supplying a predetermined processing gas into a processing chamber to form plasma, and performing plasma processing on a substrate in the processing chamber using the plasma processing gas, and more particularly to a coil used in the plasma processing apparatus. The present invention relates to a plasma processing apparatus that symmetrically converts a processing gas in a space into plasma and a coil used in the plasma processing apparatus.

Examples of the plasma treatment include a plasma etching treatment for etching a substrate (such as a silicon substrate or a silicon carbide substrate) by ions or radicals contained in the plasma-ized treatment gas, and a plasma CVD treatment for forming a thin film on the substrate. Various apparatuses have been proposed for use in performing these processes, and the applicant of the present application also employs a dielectric coupling type plasma etching apparatus used when performing a plasma etching process on a silicon substrate, for example. It has been proposed (Japanese Patent Laid-Open No. 2010-238847).

As shown in FIG. 5, the plasma etching apparatus 100 has a cylindrical shape in which a processing space 102 is set in an inner lower region, and a plasma generation space 103 communicating with the processing space 102 is set above the processing space 102. The high-frequency power is supplied to the processing chamber 101, the coil 104 disposed outside the portion of the processing chamber 101 where the plasma generation space 103 is set, the base 105 disposed in the processing space 102, and the coil 104. A coil power supply mechanism 106, a processing gas supply mechanism 107 for supplying a processing gas such as an etching gas and a protective film forming gas to the plasma generation space 103, an exhaust mechanism 108 for exhausting the gas in the processing chamber 101, and the like. A high frequency power having a predetermined frequency and magnitude is supplied to the coil 104 to generate an induction electric field and Supplying a process gas into Zuma generation space 103, the process gas into plasma by the induced electric field, a device for performing an etching process on the surface of the substrate K 'by the processing plasma gas.

JP 2010-238847 A

By the way, in the etching process using the plasma etching apparatus 100, it is preferable to perform the etching process as uniformly as possible on the entire surface of the substrate K ′ for the purpose of improving the yield. It is necessary to make the processing gas in the inside uniformly plasma, and to make the plasma processing gas uniformly act on the entire surface of the substrate K ′.

The inventors of the present invention have conducted intensive research in order to uniformly convert the processing gas in the plasma generation space 103 into plasma. As a result, it can be seen that the density distribution of the plasma generated in the plasma generation space 103 depends on the distance S ′ (see FIG. 6) between the coil 104 and the plasma generation space 103, and the distance S ′ is a little. However, it has been found that if there are different portions, the plasma density distribution in the plasma generation space 103 tends to be non-uniform. In particular, in the silicon deep etching of MEMS (micro electro mechanical system) that requires high-precision vertical processing, the uniformity of the etching sometimes becomes a problem.

As described above, the reason why the density distribution of the plasma generated in the plasma generation space 103 is non-uniform due to the presence of the slightly different distance S ′ is considered to be as follows. .

In the plasma generation space 103, when plasma is generated, an electric current flows in the plasma, and electric power resulting from the plasma is absorbed by the plasma, and the plasma of the processing gas is increased to increase the density of the plasma. When the plasma density increases, in other words, when the number of electrons and ions in the plasma increases, the electrical resistance of the plasma decreases, the power absorbed by the plasma increases, and plasmaization progresses to increase the plasma density. Will further increase. That is, once the plasma is generated in the plasma generation space 103, the processing gas is accelerated into plasma.

Therefore, when the distance S ′ between the coil 104 and the plasma generation space 103 is shortened, the induced magnetic field acting on the processing gas is also strengthened. Therefore, even if the distance S ′ is slightly short, the distance S is short. Thus, it is considered that the plasma is generated at an accelerated rate before the other portions, and as a result, the density distribution of the plasma generated in the plasma generation space 103 becomes non-uniform.

The distance S ′ between the coil 104 and the plasma generation space 103 depends on the dimensions of the coil 104 and the processing chamber 101, but the dimensional accuracy is improved over the entire circumference and the distance S ′ is strictly aligned. Is extremely difficult. In addition, the coil 104 must have two power introduction units 104a and 104b, one of which is connected to the coil power supply mechanism 106 and the other is connected to the ground, and between the two power introduction units 104a and 104b. Since there is a gap, the portion of the plasma generation space 103 corresponding to the gap between the two power introduction portions 104a and 104b inevitably becomes a singular point where the induced electric field becomes weak. For these reasons, it is extremely difficult to make the processing gas in the plasma generation space 103 into a uniform plasma. In particular, in a device that performs plasma processing on a small-diameter substrate (for example, a substrate having a diameter of 1 inch or less), if the device size is designed to match the substrate diameter, the coil size will inevitably become smaller, and power will be introduced. Since the gap between the portions becomes relatively large with respect to the size of the entire coil, it becomes more difficult to uniformly process the processing gas.

Therefore, as a result of further research, the present inventors have generated plasma so that the portion where the density is increased in the plasma generation space 103 is axially symmetric, so that the generated plasma reaches the substrate K ′. In the meantime, it has been found that the diffusion of the generated plasma proceeds uniformly, the in-plane density of the plasma is made uniform, and the plasma can finally be applied uniformly to the substrate K ′. .

The present invention has been made on the basis of the above-mentioned new knowledge, and is a plasma capable of converting the processing gas in the plasma generation space into plasma so that the portion where the plasma density in the plasma generation space is high is axisymmetric. It is an object of the present invention to provide a processing apparatus and a coil used therefor.

The present invention for solving the above problems is as follows.
A processing gas is supplied to a plasma generation space set in the processing chamber, and a high-frequency power is supplied from a coil power supply mechanism to an annular coil wound outward of a portion of the processing chamber corresponding to the plasma generation space. In the plasma processing apparatus for converting the processing gas in the plasma generation space into plasma, and plasma processing the substrate on the base with the plasma processing gas,
The coil is
Two power introduction parts, one connected to the coil power supply mechanism, the other connected to the ground, and a gap formed between them;
Having at least three inwardly extending portions that protrude toward the radially inward side of a reference circle set around the processing chamber corresponding to the plasma generation space;
The plasma processing apparatus includes the at least three inwardly extending portions formed at regular intervals along a circumferential direction of the reference circle.

According to the plasma processing apparatus of the present invention, the substrate is first placed on the base, and then the processing gas is supplied into the plasma generation space and the high frequency power is supplied to the coil.

Here, in the plasma processing apparatus according to the present invention, since at least three inward extending portions are formed in the coil, the distance between the inward extending portion of the coil and the processing chamber is greater. The distance between the processing chamber and the portion other than the inwardly protruding portion of the coil is shorter. For this reason, when high frequency power is supplied to the coil, the induced electric field acting on the part corresponding to the inward projecting part of the plasma generation space corresponds to a part other than the inward projecting part of the coil. It becomes stronger than the induction electric field that acts on the portion to be treated, and the plasma of the processing gas is likely to proceed in the portion corresponding to the inwardly extending portion, and the plasma density is increased. In addition, since at least three inwardly extending portions are formed at equal intervals along the circumferential direction of the reference circle, the portions where the plasma density is increased are aligned at equal intervals in the plasma generation space. In other words, in other words, it is in an axially symmetrical state. Note that at least three inwardly extending portions are formed at equal intervals along the circumferential direction of the reference circle that at least three inwardly extending at the same angle from the center of the plasma generation space. It is a concept that naturally includes the fact that the portions are formed symmetrically, and the plasma is also formed by forming at least three inwardly extending portions at the same angle and at the same angle from the center of the plasma generation space. The portion where the density is high is in an axially symmetrical state.

In this way, the processing in the plasma generation space is performed so that the portion where the plasma density is increased is arranged in an axisymmetric manner by providing an inwardly extending portion that is closer to the processing chamber. By turning the gas into plasma, the part where the plasma density corresponding to the singular point is low can be almost ignored, and the generated plasma reaches the substrate from the part where the density is high. Since the diffusion of the plasma to the part where the density is relatively lower than the part where the density is high, the in-plane density is made uniform. Can act.

The coil in the plasma processing apparatus is formed with at least two outwardly protruding portions extending outward in the radial direction from the reference circle along the circumferential direction of the reference circle. The gaps between the at least two outwardly extending portions, the at least three inwardly extending portions, and the power introducing portion are preferably arranged at equal intervals in the circumferential direction.

In this case, since the distance between the outward projecting portion of the coil and the processing chamber, and the distance between the gap portion between the power introduction portion and the processing chamber in the coil, respectively, the plasma generation space, The state where the induced electric field acting on the portion corresponding to the gap portion between the at least two outward projecting portions and the power introduction portion is weakened, and the portions where the plasma density is low are arranged at equal intervals in the circumferential direction, It will be in the state of being arranged symmetrically about the axis. Accordingly, since the portion where the plasma density is high and the portion where the plasma density is low are alternately arranged, the plasma is more diffused from the portion where the plasma density is high to the portion where the plasma density is low. Smoothness is achieved and uniform density is promoted. In addition, the state where the gaps between the at least two outward projecting portions and the power introduction portion are arranged at equal intervals in the circumferential direction of the reference circle are arranged at equal distances from the center of the plasma generation space and symmetrically at the same angle. The part where the plasma density is lowered also by the fact that the gap between the at least two outward projecting parts and the power introducing part at the same angle and the same angle is formed symmetrically, including the state of course, at the same distance from the center of the plasma generation space Are in an axially symmetrical state.

Moreover, even if the number of turns is 1, the coil in the plasma processing apparatus according to the present invention forms a portion where the plasma density is high, and the plasma is uniformly distributed from the portion where the plasma density is high to the portion where the plasma density is low. The coil is formed with the inwardly extending portion and the outwardly extending portion so as to protrude inward and outward along the radial direction of the reference circle. Alternatively, since the inwardly extending portion and the outwardly extending portion having the same angle are formed at the same distance from the center of the plasma generation space, the thickness in the height direction is made constant in the circumferential direction. Thus, the coil can be made compact. Therefore, it can be particularly suitably used for a small plasma processing apparatus having a restriction in the height direction, such as a plasma processing apparatus for processing a substrate having a diameter of 1 inch or less.

Here, when the number of turns of the coil is 2 or more, from the first-stage winding section to the second-stage winding section, or from the second-stage winding section to the third-stage winding section. In some cases, a transition portion that is a transition portion is formed. This transition part is a specific part of the coil. When the transition part is formed, the transition of the coil is performed only on a part of the plasma generation space corresponding to the winding part of the coil. There is a possibility that an induced electric field acts from the part.

Therefore, in the plasma processing apparatus, when the number of turns of the coil is 2 or more, the coil has a transition portion that shifts from the winding portion to the next winding portion in the gap between the power introduction portions. It is preferable that the transition portion is formed in the vicinity and projects outward in the radial direction from the reference circle.

In this way, by making the shape of the transition portion projecting radially outward from the reference circle, the induction electric field acting on the portion corresponding to the transition portion of the plasma generation space is made as weak as possible. The plasma gas density of the processing gas can be reduced, and the plasma density of only a part of the corresponding part between the coil winding parts increases in an unexpected manner. It is possible to prevent the occurrence of a problem that the balance of the plasma density is lost.

As the “substrate” in the present application, a substrate made of silicon, silicon carbide, sapphire, compound semiconductor, glass, resin, or the like can be exemplified.

As described above, according to the plasma processing apparatus of the present invention, the processing gas in the plasma generation space can be converted to plasma so that the portion where the plasma density in the plasma generation space is high is axisymmetric. .

It is the front sectional view showing the plasma treatment apparatus concerning one embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view taken along a line AA in FIG. It is sectional drawing which showed the plasma processing apparatus which concerns on other embodiment of this invention. (A) is the top view which showed the coil in the plasma processing apparatus which concerns on other embodiment of this invention, (b) is the figure seen from the arrow B direction in (a). It is a front sectional view showing a conventional plasma etching apparatus. FIG. 7 is an enlarged cross-sectional view taken along the line CC in FIG. 6.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. Note that the plasma processing apparatus of this example is a plasma etching apparatus, and performs a plasma etching process on the substrate.

As shown in FIG. 1, the plasma etching apparatus 1 of this example has a cylindrical processing chamber in which a processing space 3 is set below an internal space and a plasma generation space 4 is set above the processing space 3. 2, a processing gas supply mechanism 15 for supplying a processing gas to the plasma generation space 4, a coil 20 wound so as to surround an outer peripheral surface of a portion of the processing chamber 2 where the plasma generation space 4 is set, A coil power supply mechanism 25 that supplies high-frequency power to the coil 20, a base 30 that is disposed in the processing space 3 and on which the substrate K is placed, and a base that supplies high-frequency power to the base 30 A power supply mechanism 40 and an exhaust device 45 for exhausting the gas in the processing chamber 2 are provided.

The processing chamber 2 is composed of a lower body portion 5, an upper body portion 6, a bottom plate 7, an intermediate plate 8, a top plate 9, and a support column 10, and the lower body portion 5 has a bottom plate 7 fixed to a lower end portion thereof. At the same time, an intermediate plate 8 is fixed to the upper end, and the processing space 3 is formed by the lower body portion 5, the bottom plate 7 and the intermediate plate 8. The upper body 6 has a lower end fixed to the upper surface of the intermediate plate 8 and a top 9 fixed to the upper end. The upper body 6, the intermediate plate 8, and the top 9 make plasma. A generation space 4 is formed. Note that an opening 8a is formed in the intermediate plate 8, and the processing space 3 and the plasma generation space 4 communicate with each other through the opening 8a. In addition, a plurality of support columns 10 are provided between the intermediate plate 8 and the top plate 9.

The upper body portion 6 is made of quartz or the like, and is shaped so that the inner diameter (in other words, the outer diameter of the plasma generation space) is 15 mm or more and 50 mm or less, which is a size corresponding to the substrate K having a diameter of 1 inch or less. ing.

The lower body 6 is formed with an exhaust port 5a for exhausting the gas in the processing space 3, and the exhaust device 45 is connected to the exhaust port 5a. The gas in 2 is exhausted.

The processing gas supply mechanism 15 is connected to an etching gas supply unit 16 that supplies an etching gas such as SF ₆ gas, and one end connected to a plurality of discharge ports provided in an annular shape on the lower surface of the top plate 9, and the other end. A supply pipe 17 connected to the etching gas supply unit 16 is provided, and an etching gas is supplied from the etching gas supply unit 16 into the plasma generation space 4 through the supply pipe 17. Note that the etching gas is not limited to SF ₆ gas, and other fluorine-based gases such as CF ₄ , NF ₃ , and IF ₅ can be used.

As shown in FIG. 2, the coil 20 is wound around the outer surface of the upper body 6 on the outer side of the upper body 6, and a coil power supply mechanism 25, which will be described later, is provided at one end. The power introduction portion 20a connected to the power supply portion 20a is formed so as to be drawn out radially outward, and at the other end, the power introduction portion 20b connected to the ground is similarly formed so as to be drawn out radially outward. Yes. The two power introduction portions 20a and 20b are drawn from positions facing each other, and a gap is formed between them. In addition, the coil 20 in the plasma etching apparatus 1 of the present example has a single coplanar shape with one winding, which makes it possible to make the coil 20 compact and to reduce the magnetic field. Uniform plasma can be generated with the same orientation.

The coil 20 is bent or radially inward of a reference circle (hereinafter referred to as “pitch circle”) P set outside the portion of the processing chamber 2 corresponding to the plasma generation space 4. Six inwardly-extending portions 21 that are curved and projecting, and five outward-side projecting portions 22 that are bent or curved outward in the radial direction from the pitch circle P are continuously formed. The gap portions between the six inwardly extending portions 21, the five outwardly extending portions 22 and the power introducing portions 20a and 20b are alternately arranged along the circumferential direction of the pitch circle P, etc. In other words, the six inward projecting portions 21 and the five inward projecting portions 22 are equidistant from the center of the upper body 6 (the center of the plasma generation space 4) and at the same angle. Are alternately arranged symmetrically. The coil 20 is supported so as to be positioned approximately in the middle of the upper trunk portion 6 by a plurality of support members 23 attached to the upper surface of the intermediate plate 8.

The coil power supply mechanism 25 includes an impedance matching unit 26 connected to the power introduction unit 20a of the coil 20 and a high-frequency power source 27 connected to the impedance matching unit 26. This is a mechanism for supplying high-frequency power.

The base 30 is composed of an upper member 31 on which the substrate K is placed and a lower member 32 to which an elevating cylinder 33 is connected. The base 30 is supported by the support base 34 so as to be able to advance and retract in the vertical direction. It is disposed in the space 3 and is moved up and down by the lifting cylinder 33. The space between the outer peripheral edge of the lower surface of the lower member 32 and the upper surface of the support base 34 is covered with a bellows 35 so that the airtightness of the processing space 3 is ensured.

The base power supply mechanism 40 includes an impedance matching unit 41 connected to the base 30 and a high frequency power source 42 connected to the impedance matching unit 41, and supplies a high frequency power to the base 30. It is.

The exhaust device 45 includes a vacuum pump 46 that exhausts gas, and an exhaust pipe 47 that has one end connected to the vacuum pump 46 and the other end connected to the exhaust port 5a of the lower body 5. 45 exhausts the gas in the processing chamber 2 by the vacuum pump 46 through the exhaust pipe 47 to maintain the inside of the processing chamber 2 at a predetermined pressure.

Next, a process of performing an etching process on the substrate K (for example, a silicon substrate) using the plasma etching apparatus 1 having the above configuration will be described.

First, the substrate K having a mask with a predetermined pattern formed thereon is placed on the base 30 at the lowered position, and then the base 30 is moved up to the processing position by the lift cylinder 33, and then the exhaust device 45 is placed. By evacuating the gas in the processing chamber 2 (processing space 3 and plasma generation space 4), the processing chamber 2 is set to a negative pressure.

In parallel with this, high-frequency power is supplied from the high-frequency power source 27 to the coil 20 to generate an induction electric field in the plasma generation space 4. In this state, the etching gas supply unit 16 supplies the coil 20 in the plasma generation space 4. Etching gas is supplied. The high frequency power supplied to the coil 20 is preferably set to a frequency of 100 kHz or more and a size of 50 W or less.

Here, in the plasma etching apparatus 1 of the present example, the coil 20 is formed with an inwardly extending portion 21 and an outwardly extending portion 22, and the inwardly extending portion 21 and the outward side of the coil 20 are formed. The overhang portions 22 and the gap portions between the power introduction portions 20a and 20b are alternately arranged. Since the distance S1 from the inward projecting portion 21 to the plasma generating space 4 is shorter than the distance S2 from the outer projecting portion 22 to the plasma generating space 4, the plasma generating space 4 The induced electric field acting on the portion corresponding to the inwardly extending portion 21 (portion R1 surrounded by the broken line in FIG. 2) is the portion corresponding to the outwardly extending portion 22 (in FIG. 2). Since the induction electric field acting on the portion R2) surrounded by the dotted line is stronger and there is a gap between the two power introduction portions 20a and 20b, and the coil 20 does not exist in the gap, The induced electric field acting on the portion corresponding to the side projecting portion 22 is the induced electric field acting on the portion corresponding to the gap portion between the power introducing portions 20a and 20b (the portion R3 surrounded by the one-dot chain line in FIG. 2). Be stronger than For this reason, in the plasma generation space 4, the portion corresponding to the inwardly extending portion 21 is more than the portion corresponding to the gap portion between the outwardly extending portion 22 and the power introducing portions 20a and 20b. Plasma is easily generated.

Therefore, in the plasma etching apparatus 1 of this example, the plasma density in the portion corresponding to the inward extending portion 21 is relatively high, while the distance between the outward extending portion 22 and the power introduction portions 20a and 20b is increased. The plasma density of the portion corresponding to the gap portion is relatively low, and the high plasma density portion and the low plasma density portion are alternately arranged at equal intervals along the circumferential direction, in other words, the high plasma density portion is axisymmetric. It will be in the state arranged in.

Thereafter, high frequency power is supplied from the high frequency power source 42 to the base 30. Thereafter, the plasma-etched etching gas in which high density portions and low density portions are alternately arranged at equal intervals falls in the process of descending into the processing space 3 through the openings 8a of the intermediate plate 8. In order to smoothly diffuse from a high part to a low part, the plasma-ized etching gas reaches the substrate K in a state where the in-plane density is uniformized, and acts uniformly on the entire surface of the substrate K. . As a result, the surface of the substrate K is etched, and an etching structure is formed on the surface of the substrate K. In the etching process of this example, since high frequency power is supplied to the base 30 and a bias potential is applied to the substrate K, ions in the plasma are irradiated toward the substrate K, so-called ion-assisted etching is performed. Is called.

As described above, according to the plasma etching apparatus 1 of the present example, in the plasma generation space 4, the high plasma density portion and the low plasma density portion are alternately arranged at equal intervals, in other words, the high plasma density portion. In this state, the plasma can be diffused smoothly and plasma with uniform in-plane density can be applied to the substrate K.

As mentioned above, although one Embodiment of this invention was described, the aspect which this invention can take is not limited to this at all.

For example, in the above example, the coil 20 is formed with six inwardly extending parts 21 and five outwardly extending parts 22, but the inwardly extending part 21 and the outwardly extending part The number of the protruding portions 22 is not limited to this, and may be appropriately designed according to the size of the coil.

In the above example, the shape of the coil 20 is a shape in which the inwardly extending portion 21 and the outwardly extending portion 22 are continuously formed. However, the shape is not limited to such a shape. As shown in the coil 50 shown in FIG. 3, three inwardly extending portions 51 and two outwardly extending portions 52 are formed with a space therebetween, and the three inwardly extending

portions

51, 2 The shape which arrange | positioned the clearance gap part between the two outward side protrusion parts 52 and the two electric power introduction parts 50a and 50b alternately at equal intervals along the circumferential direction of the pitch circle P may be sufficient. Even in this case, the plasma density in the portion of the plasma generation space 4 corresponding to the inward extending portion 51 is relatively increased, and the gap between the outward extending portion 52 and the power introducing portions 50a and 50b is increased. The plasma density of the portion corresponding to the portion is relatively lowered to create a state in which the high plasma density portion and the low plasma density portion are alternately arranged at equal intervals along the circumferential direction in the plasma generation space 4. be able to.

In the above example, the number of turns of the coil 20 is set to 1, the thickness in the height direction is constant in the circumferential direction, and the coil itself is made compact, thereby etching the substrate having a diameter of 1 inch or less. In a small plasma etching apparatus 1 having a restriction in the height direction, such as a plasma etching apparatus, a remarkable effect is achieved. However, depending on the size of the apparatus, the number of turns of the coil is 2 or more. Anyway.

Here, when the number of turns of the coil is set to 2 or more, for example, a transition portion that is a specific portion that transitions from the first winding portion to the second winding portion may be formed. And when the transition part is formed, an induction electric field is generated from the transition part only in a part of the plasma generation space located between the first stage winding part and the second stage winding part. May act, and the balance of the plasma density in the plasma generation space may be easily lost.

Therefore, when the number of turns of the coil is 2 or more, as shown in FIG. 4, a transition portion 63 of the coil 60 is formed in the vicinity of the gap between the two

power introduction portions

60a and 60b, and the transition is performed. It is preferable that the part 63 has a shape projecting radially outward from the pitch circle P. In this way, the induction electric field acting from the transition portion can be weakened as much as possible to the portion of the plasma generation space 4 corresponding to the winding portion of the coil 60, and the plasma density in the plasma generation space 4 can be reduced. It is possible to suppress the occurrence of problems such as an unbalanced balance.

In the above example, the plasma processing apparatus according to the present invention is embodied as a plasma etching apparatus. However, the present invention is not limited to this. For example, a plasma CVD apparatus used when forming a thin film on a substrate is used. Alternatively, it may be embodied as a plasma ashing device used when removing the resist.

DESCRIPTION OF SYMBOLS 1 Plasma etching apparatus 2 Processing chamber 3 Processing space 4 Plasma generation space 5 Lower trunk | drum 6 Upper trunk | drum 15 Process gas supply mechanism 20 Coil 20a, 20b Power introduction part 21 Inner side extension part 22 Outer side extension part 25 Coil power supply mechanism 30 Base 40 Base power supply mechanism 45 Exhaust device 50 Coil 50a, 50b Power introduction part 51 Inner side extension part 52 Outer side extension part 60

Coil

60a, 60b Power introduction part 61 Inner side Overhang part 62 Outer side overhang part 63 Transition part

Claims

A processing gas is supplied to a plasma generation space set in the processing chamber, and a high-frequency power is supplied from a coil power supply mechanism to an annular coil wound outward of a portion of the processing chamber corresponding to the plasma generation space. In the plasma processing apparatus for converting the processing gas in the plasma generation space into plasma, and plasma processing the substrate on the base with the plasma processing gas,
The coil is
Two power introduction parts, one connected to the coil power supply mechanism, the other connected to the ground, and a gap formed between them;
Having at least three inwardly extending portions that protrude toward the radially inward side of a reference circle set around the processing chamber corresponding to the plasma generation space;
The plasma processing apparatus, wherein the at least three inwardly extending portions are formed at equal intervals along a circumferential direction of the reference circle.
The coil is formed with at least two outwardly projecting portions projecting radially outward from the reference circle along a circumferential direction of the reference circle,
The gap between the at least two outward projecting portions, the at least three inward projecting portions, and the power introduction portion is arranged at equal intervals in the circumferential direction. 2. The plasma processing apparatus according to 1.
The coil has two or more turns, and a transition part that transitions from the winding part to the next winding part is formed in the vicinity of the gap between the power introduction parts,
The plasma processing apparatus according to claim 1, wherein the transition portion protrudes outward in the radial direction from the reference circle.
A processing gas is supplied to a plasma generation space set in the processing chamber, and a high-frequency power is supplied from a coil power supply mechanism to an annular coil wound outward of a portion of the processing chamber corresponding to the plasma generation space. In the plasma processing apparatus for converting the processing gas in the plasma generation space into plasma, and plasma processing the substrate on the base with the plasma processing gas,
The coil is
Two power introduction parts, one connected to the coil power supply mechanism, the other connected to the ground, and a gap formed between them;
Having at least three inwardly protruding portions protruding in a direction approaching the plasma generation space;
The plasma processing apparatus, wherein the at least three inwardly extending portions are formed symmetrically at the same angle and the same distance from the center of the plasma generation space.
In the coil, at least two outwardly extending portions that protrude in a direction away from the plasma generation space are formed at an equal distance from the center of the plasma generation space,
The gaps between the at least two outward projecting portions, the at least three inward projecting portions, and the power introducing portion are formed symmetrically at the same angle from the center of the plasma generation space. The plasma processing apparatus according to claim 4, wherein:
The coil has two or more turns, and a transition part that transitions from the winding part to the next winding part is formed in the vicinity of the gap between the power introduction parts,
6. The plasma processing apparatus according to claim 4, wherein the transition portion projects in a direction away from the plasma generation space.
An annular coil used in a plasma processing apparatus for converting a processing gas into plasma in a plasma generation space set in a processing chamber and performing plasma processing on a substrate with the plasma processing gas,
There are two power introduction parts, and a gap is formed between the two power introduction parts,
At least three inwardly extending portions projecting radially inward from the reference circle set around the processing chamber corresponding to the plasma generation space are provided along the circumferential direction of the reference circle, etc. A coil characterized by being formed at intervals.
At least two outward projecting portions projecting radially outward from the reference circle are formed along the circumferential direction of the reference circle;
The gap between the at least two outward projecting portions, the at least three inward projecting portions, and the power introduction portion is arranged at equal intervals in the circumferential direction. 7. The coil according to 7.
The number of turns is 2 or more, and a transition part that transitions from the winding part to the next winding part is formed in the vicinity of the gap between the power introduction parts,
The coil according to claim 7 or 8, wherein the transition portion projects outward in the radial direction from the reference circle.
An annular coil used in a plasma processing apparatus for converting a processing gas into plasma in a plasma generation space set in a processing chamber and performing plasma processing on a substrate with the plasma processing gas,
There are two power introduction parts, and a gap is formed between the two power introduction parts,
The coil is characterized in that at least three inwardly projecting portions projecting in a direction approaching the plasma generation space are formed symmetrically at the same angle and at the same angle from the center of the plasma generation space.
At least two outward projecting portions projecting away from the plasma generation space are formed at equal distances from the center of the plasma generation space;
The gaps between the at least two outward projecting portions, the at least three inward projecting portions, and the power introducing portion are formed symmetrically at the same angle from the center of the plasma generation space. The coil according to claim 10.
The number of turns is 2 or more, and a transition part that transitions from the winding part to the next winding part is formed in the vicinity of the gap between the power introduction parts,
The coil according to claim 10 or 11, wherein the transition portion projects in a direction away from the plasma generation space.